<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        .container{
            width: 500px;
           
            background-color: red;
        }

        .box{
           width: 100px;
           height: 100px;
           background-color: yellow;
           margin: 5px;
           float: left;
        }
        .text{
            width: 100px;
            height: 100px;
            background-color: blue;
            clear: both;
        }
    </style>
</head>
<body>
    <div class="container">
        <div class="box"></div>
        <div class="box"></div>
        <div class="box"></div>
        <div class="text"></div>
    </div>
</body>
</html>